The subject matter disclosed herein relates generally to capacitors and, more specifically, to multi-plate capacitors embedded within printed wiring boards (PWBs), also known as printed circuit boards (PCBs).
Electronic devices generally include a variety of components, including capacitors, mounted to a PWB. At least some known PWBs include an embedded capacitor that uses conductive layers of the PWB (e.g., a ground plane and a power plane) as capacitor plates. Such an embedded capacitor may eliminate the need to mount a capacitor to a surface of the PWB. However, at least some known embedded capacitors require a relatively large portion of the PWB to be dedicated to the capacitor, or require that the PWB be sized sufficiently to achieve a desired capacitance. Such a design may be infeasible for a smaller-sized PWB, such as a PWB designed for use in a mobile electronic device. In such a PWB, the capacitor may occupy so much of the PWB that insufficient space remains for other electronic components to be mounted on the PWB. Moreover, known embedded capacitors may exhibit a relatively high inductance, such that the capacitor becomes ineffective at high frequencies (e.g., above 40 megahertz). In addition, a conventional surface-mounted capacitor may be subjected to physical stress as the surface-mounted capacitor and the underlying PWB expand at different rates, whereas a capacitor embedded within a PWB may expand at substantially the same rate as the PWB to which it is mounted.